Add a github workflow plus some cleanups

.github/workflows/workflow.yaml

@@ -0,0 +1,43 @@
+name: Continuous integration
+on: [push]
+env:
+  # Bump this number to invalidate the GH actions cache
+  cache-version: 0
+
+jobs:
+  test-nixpkgs:
+    name: Build & Test - Nixpkgs
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Mount Bazel cache
+        uses: actions/cache@v2
+        with:
+          path: ~/repo-cache
+          key: repo-cache-${{ runner.os }}-nixpkgs-${{ env.cache-version }}
+      - uses: cachix/install-nix-action@v12
+        with:
+          nix_path: nixpkgs=./nixpkgs.nix
+      - name: Configure
+        env:
+          BUILDBUDDY_API_KEY: ${{ secrets.BUILDBUDDY_API_KEY }}
+        run: |
+          cat >.bazelrc.local <<EOF
+          build --host_platform=@io_tweag_rules_nixpkgs//nixpkgs/platforms:host
+          build --bes_results_url=https://app.buildbuddy.io/invocation/
+          build --bes_backend=grpcs://cloud.buildbuddy.io
+          build --remote_cache=grpcs://cloud.buildbuddy.io
+          build --remote_header=x-buildbuddy-api-key="$BUILDBUDDY_API_KEY"
+          build --repository_cache=~/repo-cache/
+          EOF
+          ln -s ../.bazelrc.local example/.bazelrc.local
+      - name: Build & run gazelle
+        run: cd example; nix-shell --pure --run 'bazel run //:gazelle'
+      - name: Build & test generated rules
+        run: cd example; nix-shell --pure --run 'bazel test //...'
+      - name: Test for buildifier suggestions
+        run: nix-shell --pure --run 'bazel run //:buildifier-diff'

BUILD.bazel

@@ -4,6 +4,7 @@ exports_files(["defs.bzl"])
 
 buildifier(
     name = "buildifier-diff",
+    diff_command = "diff -u",
     mode = "diff",
 )
 

README.md

@@ -215,36 +215,6 @@ haskell_module(
 )
 ```
 
-## What's next
-
-- [X] Have `haskell_module` rules depend on each other.
-- [X] Investigate how to index external repositories, which would be needed
-  to recognize the provenance of modules coming from external dependencies.
-- [X] Have Haskell rules depend on `haskell_module` rules
-- [X] Copy `extra_srcs` from the originating rule
-- [X] Copy `tools` from the originating rule
-- [X] Copy `plugins` from the originating rule
-- [X] Skip CPP directives when scanning for imports
-- [X] Have a story for preprocessed modules like those needing tasty-discover
-- [X] Update `haskell_module` rules when imports change
-- [X] Solve interferences with `gazelle_cabal` (removes keep comments on srcs, libsodium label is not understood, deps attribute is reset)
-- [X] Lift restriction to name only `haskell_module` rules with dots.
-- [X] Lift restriction to name custom `haskell_module` rules as `<package>.<module>`
-- [X] Propagate compiler flags and other attributes of libraries, tests, and binaries, to `haskell_module` rules listed in the dependencies.
-- [X] Use the `modules` attribute of `haskell_library` instead of `deps`
-- [X] Address feedback from code review session.
-- [X] Implement gazelle directive to erase library boundaries
-- [X] Implement gazelle\_haskell\_modules:keep
-- [ ] Check if linker options need special treatment
-- [ ] Copy `data` from the originating rule (?)
-- [X] Document how `gazelle_haskell_modules` works
-- [X] Support the fix command to remove outdated `haskell_module` rules
-- [X] See whether we can run `gazelle_haskell_modules` and `gazelle_cabal` in one pass
-- [ ] Implement tests
-- [ ] Setup CI
-- [X] Have himportscan support lhs files
-- [ ] Move the update-repos feature of gazelle\_cabal to gazelle\_haskell\_modules
-
 ## Sponsors
 
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

example/WORKSPACE

@@ -25,7 +25,6 @@ rules_haskell_dependencies()
 load(
     "@io_tweag_rules_nixpkgs//nixpkgs:nixpkgs.bzl",
     "nixpkgs_local_repository",
-    "nixpkgs_package",
     "nixpkgs_python_configure",
 )
 
@@ -122,42 +121,3 @@ http_archive(
 load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
 
 gazelle_dependencies()
-
-####################
-# zlib
-####################
-
-#nixpkgs_package(
-#    name = "nixpkgs_zlib",
-#    attribute_path = "zlib",
-#    repository = "@nixpkgs",
-#)
-#
-#nixpkgs_package(
-#    name = "zlib.dev",
-#    build_file_content = """
-#load("@rules_cc//cc:defs.bzl", "cc_library")
-#
-#filegroup(
-#    name = "include",
-#    srcs = glob(["include/*.h"]),
-#    visibility = ["//visibility:public"],
-#)
-#
-#cc_library(
-#    name = "zlib",
-#    srcs = ["@nixpkgs_zlib//:lib"],
-#    hdrs = [":include"],
-#    strip_include_prefix = "include",
-#    visibility = ["//visibility:public"],
-#    # This rule only bundles headers and a library and doesn't compile or link by itself.
-#    # We set linkstatic = 1 to quiet to quiet the following warning:
-#    #
-#    #   in linkstatic attribute of cc_library rule @zlib.dev//:zlib:
-#    #   setting 'linkstatic=1' is recommended if there are no object files.
-#    #
-#    linkstatic = 1,
-#)
-#""",
-#    repository = "@nixpkgs",
-#)

example/package-a/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@rules_haskell//haskell:defs.bzl", "haskell_binary", "haskell_toolchain_library")
+load("@rules_haskell//haskell:defs.bzl", "haskell_binary")
 
 # a-haskell-binary and another-haskell-binary use the same files
 #
@@ -64,3 +64,13 @@ haskell_module(
     name = "non-enclosed-module",
     src = "app/Main.hs",
 )
+
+sh_test(
+    name = "test-a-haskell-binary",
+    srcs = [":a-haskell-binary"],
+)
+
+sh_test(
+    name = "test-another-haskell-binary",
+    srcs = [":another-haskell-binary"],
+)

gazelle_haskell_modules/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "gazelle_haskell_modules",
@@ -14,12 +14,9 @@ go_library(
         "@bazel_gazelle//config:go_default_library",
         "@bazel_gazelle//label:go_default_library",
         "@bazel_gazelle//language:go_default_library",
-        "@bazel_gazelle//language/go:go_default_library",
-        "@bazel_gazelle//language/proto:go_default_library",
         "@bazel_gazelle//repo:go_default_library",
         "@bazel_gazelle//resolve:go_default_library",
         "@bazel_gazelle//rule:go_default_library",
-        "@bazel_gazelle//walk:go_default_library",
         "@com_github_bazelbuild_buildtools//build:go_default_library",
         "@io_bazel_rules_go//go/tools/bazel:go_default_library",
     ],

gazelle_haskell_modules/dependency_resolution.go

@@ -4,15 +4,9 @@ package gazelle_haskell_modules
 import (
 	"fmt"
 
-	//"github.com/bazelbuild/buildtools/build"
-	//"github.com/bazelbuild/bazel-gazelle/config"
 	"github.com/bazelbuild/bazel-gazelle/label"
-	//"github.com/bazelbuild/bazel-gazelle/language"
-	//golang "github.com/bazelbuild/bazel-gazelle/language/go"
-	//"github.com/bazelbuild/bazel-gazelle/language/proto"
 	"github.com/bazelbuild/bazel-gazelle/resolve"
 	"github.com/bazelbuild/bazel-gazelle/rule"
-	//"github.com/bazelbuild/bazel-gazelle/walk"
 
 	"log"
 	"path/filepath"

gazelle_haskell_modules/rule_generation.go

@@ -48,7 +48,7 @@ func nonHaskellModuleRulesToRuleInfos(
 		if !isNonHaskellModule(r.Kind()) || !shouldModularize(r) {
 			continue
 		}
-		srcs, err := srcsFromRuleExceptKeep(pkgRoot, r.Attr("srcs"))
+		srcs, err := srcsFromRule(pkgRoot, r.Attr("srcs"))
 		handleRuleError(err, r, "srcs")
 
 		modules, err := depsFromRule(r.Attr("modules"), repo, pkg)
@@ -196,7 +196,7 @@ func addNonHaskellModuleRules(
 				}
 			}
 
-			srcs, err := srcsFromRuleExceptKeep(pkgRoot, r.Attr("srcs"))
+			srcs, err := srcsFromRule(pkgRoot, r.Attr("srcs"))
 			handleRuleError(err, r, "srcs")
 			modules, err := depsFromRule(r.Attr("modules"), repo, pkg)
 			handleRuleError(err, r, "modules")
@@ -253,17 +253,9 @@ func concatRuleInfos(xs [][]*RuleInfo) []*RuleInfo {
 	return ys
 }
 
-func NotShouldKeep(expr build.Expr) bool {
-	return !rule.ShouldKeep(expr)
-}
-
-func ConstTrue(expr build.Expr) bool {
-	return true
-}
-
 // Collects the source files referenced in the given expression
-func srcsFromRuleExceptKeep(pkgRoot string, expr build.Expr) ([]string, error) {
-	srcs, err := getSources(expr, NotShouldKeep)
+func srcsFromRule(pkgRoot string, expr build.Expr) ([]string, error) {
+	srcs, err := getSources(expr)
 	if err != nil {
 		return nil, err
 	}
@@ -358,8 +350,8 @@ func ParseLabel(v string) (label.Label, error) {
 	return label.Parse(v)
 }
 
-func getSources(expr build.Expr, p func(build.Expr) bool) (map[string]bool, error) {
-	xs, err := getStringListP(expr, p)
+func getSources(expr build.Expr) (map[string]bool, error) {
+	xs, err := getStringList(expr)
 	if err != nil {
 		return nil, err
 	}
@@ -374,9 +366,7 @@ func getSources(expr build.Expr, p func(build.Expr) bool) (map[string]bool, erro
 // but yields an empty list if the attribute isn't set, and
 // gives an error if the attribute is set to something that
 // isn't a list.
-//
-// Yields only the values satisfying the given predicate.
-func getStringListP(expr build.Expr, p func(build.Expr) bool) ([]string, error) {
+func getStringList(expr build.Expr) ([]string, error) {
 	switch expr.(type) {
 	case nil:
 		return []string{}, nil
@@ -387,9 +377,7 @@ func getStringListP(expr build.Expr, p func(build.Expr) bool) ([]string, error)
 			switch e.(type) {
 			case *build.StringExpr:
 				estr := e.(*build.StringExpr)
-				if p(estr) {
-					xs = append(xs, estr.Value)
-				}
+				xs = append(xs, estr.Value)
 			default:
 				return nil, fmt.Errorf("Unhandled expression type %T (expected a string)", e)
 			}
@@ -400,10 +388,6 @@ func getStringListP(expr build.Expr, p func(build.Expr) bool) ([]string, error)
 	}
 }
 
-func getStringList(expr build.Expr) ([]string, error) {
-	return getStringListP(expr, ConstTrue)
-}
-
 func isNonHaskellModule(kind string) bool {
 	return kind == "haskell_library" ||
 		kind == "haskell_binary" ||

shell.nix

@@ -12,6 +12,7 @@ mkShell {
     bazel_4
     binutils
     cacert
+    diffutils # for buildifier-diff
     git
     nix
     openjdk11